The invention relates to a miniature diaphragm sealing bag device for a shield sharp turn in a strong permeable stratum and a construction method, wherein the device comprises a grouting device and aminiature diaphragm sealing bag, the grouting device comprises a check valve, an outer cylinder, an inner cylinder, a grouting pipe, a sealing gasket and the like, the miniature diaphragm sealing bagis positioned on the outer side of the grouting pipe and can be freely expanded through grouting. The miniature diaphragm sealing bag device provides an auxiliary turning function for shield sharp curve construction of a strong permeable stratum, the expansion volume of the diaphragm bag is designed according to the turning radius and the grouting amount is determined, the slurry is pressed into the miniature diaphragm sealing bag by the grouting device through a shield segment reserved hole, the diaphragm bag is gradually expanded to a proper volume, the gap between the segment and the stratum is quickly filled, the segment position during the rapid curve turning of the shield can be fixed, the posture of the shield is adjusted, and the accuracy of the turning axis is ensured.